Buffing element with metallic center



May 19, 1959 I A. s. ROCK BUFFING ELEMENT WITH METALLIC CENTER 2 Sheets-Sheet l Filed Aug. 8. 1957 M M WM-44 flas y 19, 1959 A. s. ROCK BUFF'ING ELEMENT WITH METALLIC CENTER 2 Sheets-Sheet 2 1119.6.

Filed Aug. 8. 1957 Unit States atent 2,886,924 Patented May 19, 1959 2,886,924 BUFFING ELENIENT WITH METALLIC CENTER Albin 5. Rock, East Bridgewater, Mass., assiguor to F. L.

& J. C. (Iodmau Company, Rockland, Mesa, a corporation of Massachusetts Application August 8, 1957, Serial No. 677,053 7 Claims. (Cl. 51-193) This invention relates to bufiing elements and, more particularly, those of the so-called rufiled buff type comprising an annulus of bufiing material secured by a mechanical grip of a metallic center which may be readily dismantled to release the annulus after wear. A so-called rufiled bufi is usually made from an effectively continuous ring comprising a strip of bias fabric wound on itself in the form of a cylinder and comprising a multiplicity of plies. The sides of the ring are folded outwardly along a center line with concomitant compaction of the material adjacent that line, and usually, although in lesser degree, throughout the width of the rings to provide two flat annuli side by side, having pleatings or rufilings pro duced incident to the transformation in form of the ring. This duplex annulus is mounted on a supporting center of one kind or another.

Such a device is in a sense a bufliing wheel and might be used alone, but since it has a relatively narrow face, it usually in practice will be what is termed a section, adapted to be assembled with other sections to form a buffing wheel or cylinder having an external cylindrical working face of comparatively great width.

Such an element wears rapidly in use. In production work a large fraction of the radial depth of the buffing wheel is worn away in a period measured in hours. If the user has such a use for it, it may be shifted to another job with different demands for a further period of use and wear, but in general, even if so extended, its useful life is short. It cannot be worn away right down to the center. The bufling material is usually mounted on the center in a permanent manner, whether the center is made of fiber board of various kinds or is an expendible metal center and the section is considered as a single use or ex pandible device. It may have some salvage value, but the parts are not recovered except with considerable labor and in a deteriorated condition unfitting them for new uses comparable to the old.

In accordance with the invention 2. buff is provided supported by a metallic center of substantial inherent strength and firmly holding the annulus in a mechanical grip in such a manner as not materially to afiect the integrity of the material of the annulus. It may, moreover,

be readily dismantled to release the annulus without darnage, whereby the fabric is salvaged in good shape for re-use as described in my application, Serial No. 639,800, filed February 12, 1957, of which the present application is a continuation in part. The center comprises two mem- I bers which themselves are secured together to provide for the desired mechanical grip and, in general, one or both ofthe members when they are separated on dismantling of the element will be capable of reuse. While they are inexpensive they are, nevertheless, elements of substantial strength and rigidity as distinguished from .mere bindings of thin metal clampedabout the margin of a fabric annulus, and they may be separated without disruption or impairment of their general form.

The invention will be well understood by reference to the drawings showing by way of example a preferred illustrative embodiment of the invention wherein:

Fig. 1 is a side elevation showing one face of the bufiing element and its supporting center, which face, merely for differentiation, is here called the obverse face;

Fig. 2 is a fragmentary side elevation showing the opposite or reverse face;

Fig. 3 is a section on line 33 of Fig. 1 on a larger scale;

Fig. 4 and Fig. 5 are fragmentary radial sections on a much larger scale on lines 4--4 and 5-5 of Fig. 7 respectively;

Fig. 6 is a schematic view corresponding to Fig. 4, although on a smaller scale showing the parts separated;

Fig. 7 is an enlarged section on line 7-7 of Fig. 2 viewed radially;

Figs. 8 and 9 are radial sections corresponding to Figs. 4 and 5 showing a modification; and

Fig. 10 is a schematic view consisting of diametric sections illustrating phases of utilization of a body of buffing material.

Referring to Figs. 1 and 2, there is there shown a buffing element comprising an annulus of buffing material 15 which, in the form in which the element is originally manufactured and supplied to. the trade, as distinguished from a re-issued form embodying fabric salvaged from used buffs, consists of two annuli 15-0 and 15-r set side by side (see Fig. 3) and formed by folding a substantially cylindrical ring or band (like a napkin ring) of a width twice that of the radial depth of the finished annulus in the wheel. In contrast with many buffs, the inner circumference of the annulus is not impregnated with plastic or stifiening material along its inner periphery to consolidate that portion in a solid mass, nor are fastening means used which might affect the integrity of the material and which could be withdrawn only at prohibitive labor costs and with probable further impairment of that integrity when the fabric of the partially worn buff is salvaged for re-use. In contrast with such practice the annuli 15-0 and 15-r, when brought to the form shown in Fig. 5, are mechanically held at their inner circumference and effectively secured by a center formed by initially separate metallic members 19 and 21 which are closed thereon, which center may be dismantled readily after use to release the annuli when they have been worn down to a lesserradial depth, say one equal to one-half of the original depth, but otherwise, except for the rufiling or pleating which may readily be extended and flattened out, essentially like new.

In Fig. 10 there is shown schematically the transformation of a ring of buffing material into an annulus like 15 suitable for mounting on a center to provide a ruffled buff, the effect of wear on the annulus, salvage of the worn material and its incorporation in a new .buif. Thus in Fig. 10a there is illustrated a plied cylindrical ring of fabric which, when in cylindrical form, has a diameter much greater than that of the inner circumference of the annulus to be made therefrom, and usually, as here indicated, greater than the external diameter. The thickness of the band is exaggerated. This ring may be folded centrally and compacted by rolling to the form shown in Fig. IO-a, forming a duplex annulus of two parts like 15-0 and 15- r, side by side, which is mounted on a center to form the buff section. Fig. l0-c shows such an annulus worn down to about half its original radial depth. i i

Fig. 10-d shows the material in 10-0 after release from the center, unfolded and expanded to a cylindrical form, which has the same diameter as the original ring in 10-1: and half the width.

Fig. l0-e shows two such rings placededge to edge and united herein by atape 17bridging these. edges and with spurs aseasaa 'On account of the small scale the tape is indicated by'a single line, and it is convenient to show it on the outside of the band but a portion of the center of the band has been broken away to illustrate the tape in elevation. Theaddition of the tape causes no substantial increase in bulk along the center line. This compound band is of the same diameter and the same width as the unitary band of Fig. la and may be folded outwardly along the center line and ruflled to bring it into a form corresponding to Fig. 104:. This may be attached to a center and, if to one of the same construction of center as the original, will produce a new section essentially like the original. The face of the worn down section of Fig. lO-c would be'impregnated for a substantial depth'with buffing compound incident to its use. When two such strips are salvaged and re-used in the manner described, the edge of the reconstituted section of Fig. e will be already saturated, which is not a disadvantage, but rather an advantage, since new wheels must be broken in in any event.

The preferred form of metallic center illustrated in Figs. 1 through 7 comprises two members, an obverse member 19 and a reverse member 21 made of metal, which is sheet metal but nevertheless of substantiai strength and rigidity in the completed members, which members when fitted together define a radially outwardly opening channel in which the internal circumferential edge of the annulus is received, and having a base portion underriding the same and flanges overlying its radial'faces and mechanically gripping the same by means to be described.

The obverse member 19 comprises a radial flange 23 and a base flange 25 of frustro-conical form'including toward the center at a small angle, say eleven degrees. This means that the base angle of the cone is seventynine degrees and the internal angle betweenradial flange '23 and base flange 25 is one hundred and one degrees. The flange 25 extends unbroken to about the center line of the section, but the frustro-conical surface is continued to provide spaced projections 27 (eight in the example) having a depth about equal to the gage of the metal. Integrally extending from each of these projections are several long, rather narrow tongues 29, which initially may lie in the same conical surface as seen in Fig. 6. The radial flange 23 is provided with integral spurs 31 extending from the outer margin inwardly at right angles parallel to the axis of the wheel, hereinafter more fully to be described.

As best seen in' Fig. 7 this radial flange 23 may have radial corrugations 33 and as seen in Fig. 4 the inward indentations of the corrugations are opposite the roots of the spurs 31 and extend into the bases thereof, stifiening the spurs.

The reverse member 21 has a radial flange 41 and a frustro-conical flange 43. This flange 43 extends unbroken and intersects the unbroken edge of flange 25, these unbroken parts being of the same width. The frustro-conical surface is continued to provide circumferentially spaced portions 45 which in the example shownalternate with and are received between portions 27 -and vice versa. That is, the edges of the two base flanges 25 and 43 are interdigitated and form a mortise and tenon joint. If the two hands are clasped together with the palms facing each other at an angle and the fingers interlaced, the proximal phalanges of the fingers are related together in this manner. The edge of one frustrum bears against the extensions of the other and the two base flanges .in radial planes around their circumferences take the form of inwardly presented transverse arches. The outer edge .of radial flange 41 is provided 47 extending .inwardly at right angles and parallel to .the axis ofthe wheel, similar to the spurs 27 of radial flange 23 of the other member.

In the .constructionshownin .Figs. 1-7 the channel formed by the two cooperating parts is designed 1 for united thereto bysewing.

support from a spindle of relatively small diameter. Herein the extensions 45 of flange 43 of the reverse member 21 integrally join radially extending spoke-like members 49 which merge at their inner ends with a central disc El, from which is formed a cylindrical sleeve or nave 53 to fit such a spindle. The spokes may be strengthened by impressed ribs 55 which extend into the disc (Fig. 1) and through the parts 45, Fig. 7.

To mount the annulus on the center the two members 19 and 21 may be placed in axial alignment at opposite side of the inner circumferential portion of the duplex annulus 15 as shown in Fig. 6. The interior radius of the annulus corresponds substantially to the radius of the bottom of the channel to be formed by the two members. The two members are then brought together axially tightly to embrace and clamp the annulus as seen in Figs. 4 and 5, the edges of the base flanges 23 and 43 being brought together with the projections 27 and 45 meshing in an interdigitated joint as described. The two are then locked together by bending the tongues 29 (which when the parts are being brought together move easily through the spaces between the spokes 49 of the reverse member, see Fig. 2) outwardly against the inwardly facing surface of the base flange 43 and then radially across the outer surface of radial flange 41 and pressed axially in gripping engagement with the latter. Since the tongues are rather narrow in the circumferential direction they readily bend as described, without rolling or swaging of the metal in a circumferential direction, and their ends when directed outwardly will flare and be disposed substantially uniformly around the circumference of the circle.

When the two members are brought together in this manner the spurs 31 and 47 enter into the body of bufling material 15. These spurs are out of line in the respective two elements so they do not interfere with one another. They are preferably triangular in form as seen in Fig. 6 and are of a length to extend at least substantially to, and conveniently somewhat beyond, the center liner of the completed section, so that each set of spurs engages the adjacent annulus 15 substantially throughout the thickness of the same. The fabric material is tightly compacted in pleatings or rufllings along the inner diameter, which rufl'lings however are in a sense free from one another. In practice the spurs appear to find their way into the interstices of the rufflings without laceration of the material itself except to a negligible amount. After clamping together of the center forming members 19 and 21, the material is firmly held in its upset or ruflied form to secure a mechanical interlock with the annulus, the spurs preventing displacement of the bufling material under the stresses occurring in use.

It is pointed out that the spurs have no rearwardly presented shoulders which, on dismantling of the section, might catch and lacerate the material in separating the center forming members from the buifing annuli. The inwardly facing crests of corrugations 33 of flange 23 will also press into the base of the adjacent annulus and interlock with the same. Here again however the form of the corrugations is such that they neither injure the material when the members are brought together, nor when they are separated or dismantled.

In applying the two members to the internal circumference of the annulus 15 the frustro-conical form of the base flanges facilitates their moving in past the sides of the annulus and when these base flanges come into'contact they provide a slight clearance at the center into which surplus material may be compacted. The tongues 29 pass freely through the wide openings between the spokes 49, two tongues between each pair of spokes'in the form shown. The exterior diameter of disc 51 is less than the smallest diameter of the circuit of tongues in the unbent position of Fig. 6. No threading'through narrow slots .is involved. The circuit of tongues-centers itsmember relativeto the othe The two bends :which press the tongues against the interior'face of base flange 43 and the axially-exposed extending face of radial flange 41 are each less than a right angle (that is, the resultant interior angle is greater), no reverse bend is made and no bend is made around a sharp edge.

In the preferred form shown projections 27 on which the tongues 29 are based continue the frustro-conical sut face of their base flange 25, and the projections 45 on which the spokes 49 are based continue the frustro-conical surface of their base flange 43, each set of projections constituting tenons or merlons received in the mortises or crenels formed in the edge of the other surface. In the construction shown the tongues are arranged in groups of two and the space between the two as seen in cut back through the projections 27,

Fig. 7 has been which in one sense then provide are here termed the tongues. The first bend of the tongues 29 starts in the plane at the edge surface of projections 27 (which cross the edge of flange 43) and the inward bends of the spokes 49 start in the plane of the edge surface of projections 45 and in a plane therefore slightly offset from the center plane of the element. The metal involved is thin and the bends obviously are not the geometrically sharp angles between two lines, but in practice the ideal is approximated. The tongues in any instance must cross the other flange 43 and because the smaller diameters of the frustra are circles, the interiorly positioned one will ultimately underride and support the exteriorly positioned one.

The two members 19 and 21 of the center may be separated and the section dismantled by unbending the tongues 29 and separating the two members axially. It would of course be tedious to pry up the ends of these tongues manually with a screwdriver in an individual case, but under production conditions it is easy, by means of a suitable appliance, to exert inward or centripetal force thereon to straighten them out. It may be noted that, particularly when the proximal portions of these tongues are not radially supported, a direct radial pressure on their ends tends to start them bending along their line of junction with the extensions 27 of base flange 25, moving their ends outwardly from the radial flange 41 against which they are pressed, and facilitating a continuation of a straightening movement. They may be pressed down against a suitable support which is a continuation of the frustro-conical surface of base flange into substantially their original position (see in Fig. 6) which they occupied before bending.

It has been pointed out that, while the two members 19 and 21 are of sheet metal, they are nevertheless of substantial strength and rigidity. They are not tinny, mere edge bindings clinched to a fabric body. Thus, by way of example and without limitation, in the case of a section of 14" diameter cold drawn sheet steel .042" thick may be recommended. When the fabric portion is salvaged for re-use in a reconstructed section, the economy resulting therefrom is such as to permit this to be done even if the center is scrapped when first removed, that is, is considered as expendible. However, the reverse member 21 obviously is recovered unimpaired. The obverse section 19 may require a closer inspection and possibly a reshaping of the tongues 29, although the metal is such that it would stand several bendings with out appreciable weakening, particularly when the shape of the channel as shown is such that the bends are greater than the right angle and are not made about any sharp edge. Under particular conditions of course a slight additional labor charge could be justified, since the parts are to be used only twice. In any instance the manufacturer will receive back two centers for each reissued bufling element and the dismantling, justified alone by the salvage of the valuable bufling material, will also at least supply him with a marketable supply of clean segregated scrap. Probably it would be preferred in any event to use new centers for original elements.

separate roots for what Referring to Figs. 8 an'cl9, these show a form of center which may be used when the sections are supported on a rather large drum instead of a shaft of relatively small diameter. The spoke forming portions 49 and the disc 51 of which they form a part, are done away with and the reverse member 21-1: and the obverse member 19-a are otherwise like those of the other modifications, the base flanges being frustro-conical as there, and having interdigitated edges.

It might be thought that, since the interior circumference of the rim section is not flat, this would be a disadvantage, as it would not have a full length bearing on the shaft. However, when a number of sections are assembled to form a wheel of wide face, they would be clamped closely together and bear on the shaft at a multiplicity of closely arranged spaces and the section, whether used alone or in combination with others, would be supported in radial position by end plates. On the contrary, the'r'elief of the internal circumference of the rim may be an advantage when it comes to placing the sections over the end of the supporting drum.

When a number of sections are assembled to form a wheel of relatively great width the corrugations 33 at the obverse face, as seen in Fig. 1, provide exteriorly radial passageways to permit air, entering through the spaces between the spokes, to pass out between the sections and keep them cool. The outwardly facing crests of the corrugations bear on the fiat faces of the turned over tongues 29 of an adjacent section, which tongues are in such number as to occupy substantially all the circumference between the spokes, as seen in Fig. 2, and provide an even bearing for the corrugations and the ends of the tongues also serve as spacing elements cooperating with the corrugations to increase the size of the airways.

This application is a continuation in part of application 639,800 filed February 12, 1957, wherein the process herein disclosed is claimed.

I am aware that the invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and I therefore desire the present embodiment to be considered in all respects as illustrative and not restrictive, as is in fact clear in several matters from the description itself. Reference is to be had to the appended claims to indicate those principles of the invention exemplified by the particular embodiment described and which I desire to secure by Letters Patent.

What is claimed is:

1. A rotary buifing element comprising an annulus of bufflng material and means for supporting and positioning the same consisting of two companion sheet metal members mechanically interlocked to provide a channel opening radially outwardly in which channel the internal portion of the annulus is received and in which it is mechanically secured, the said members each comprising a radial flange opposing the respective sides of the annulus and having inwardly projecting at substantially right angles to their inner faces means for indenting and interlocking the material of the annulus, which means are free of rearwardly facing shoulders so that they may enter the mass of buffing material on axial approach of the two flanges and be withdrawn freely therefrom when the two flanges are axially separated, base flanges extending inwardly from the inner peripheries of the radial flanges to underride the internal circumference of the annulus, the base flanges having interdigitated edges, the interdigitated portions of at least one flange being continued as extensions bent over the other base flange and against the radial flange arising from said other base flange for mechanically securing the members together and holding the annulus of buffing material by a mechanical grip.

2. An element as set forth in claim 1 wherein the interdigitated portions of one flange have extensions as set forth in that claim and those of the other flange are bent radially inward to provide spoke-like portions in a plane substantially central between the two radial flanges,

7 the said portions defining spaces between them through which said extensions extend, and a disc connecting the inner ends of the spoke-like portions having centrally a cylindrical bearing for a supporting shaft.

3. A rotary bufling element comprising an annulus of bufling material and means for supporting and positioning the same consisting of two companion sheet metal members mechanically interlocked to provide a channel opening radially outwardly in which channel the internal portion of the annulus is received .and in which it is mechanically secured, the said members each comprising a radial flange opposing the respective sides of the annulus and having inwardly projecting at substantially right angles to their inner faces means for indenting and interlocking the material of the annulus, which means are free of rearwardly facing shoulders so that they may enter the mass of bufling material on axial approach of the two flanges and be withdrawn freely therefrom when the two kanges are axially separated, tfrustro-conical base flanges extending from the inner peripheries of the radial flanges inwardly toward the center of the elements with their smaller bases engaging in mutually apposing contact in the radial plane lying substantially centrally between .said radial flanges, one of the said base flanges having at its inner edge a circumferential series of tongues crossing the apposed edge of the other base flange and bent over the under surface of the latter and against the outer surface of the radial flange arising therefrom for mechanically securing the members together and holding the annulus of bufling material by a mechanical grip.

4. A rotary bufling element comprising an annulus of bufling material and means for supporting and positioning the same consisting of two companion sheet metal members mechanically interlocked to provide a channel opening radially outwardly in which channel the internal portion of the annulus is received and in which it is mechanically secured, the said members each comprising a radial flange opposing the respective sides of the annulus and having inwardly projecting at substantially right angles to their inner faces means for indenting and interlocking the material of the annulus, which means are free of rearwardly facing shoulders so that they may enter the mass of bufling material on axial approach of the two flanges and be withdrawn freely therefrom when having edge portions disposed in substantially radial planes, said edge portions making mutual apposed contact substantially in the radial plane lying centrally be tween the two radial flanges andlimiting the inward movement of base flanges and radial flanges axially toward one another, at least one of the flanges having a series of circumferentially spaced tongues integral therewith and extending across the zone of contact and bent over against the inwardly facing surface of the other flange and against the exterior face of the radial flange arising from said other flange for mechanically securing the members together and holding the annulus of bufling material by a mechanical grip.

5. A center for supporting an annulus of bufling material comprising two laterally adjacent, generally circular sheet metal members having peripherally disposed portions which cooperatively form an outwardly opening channel to receive the annulus, at least one of the members including a central portion providing a bearing to receive a shaft, said portion having openings at intervals therearound defining spoke-like parts supporting the channel-forming portions, the companion member having tongues which extend across the bottom of the channel, pass through said openings and are terminally bent upon the radial flange of the first member.

6. A center as set forth in claim 5 wherein the radial flange of the said one member and the tongue parts bearing against it are flat and the channel flange of said companion member is corrugated to define outwardly extending grooves across its external face.

7. A center as set forth in claim 6 wherein the radial flanges of the channel have integral inturned teeth and the grooves are aligned with the teeth of the flange in which they are formed and extend into the bases of the teeth to stiffen the latter.

References Cited in the file of this patent UNITED STATES PATENTS 

